In recent years, remote energy saving services mainly targeted at buildings are provided. Remote energy saving services are services that provide power supply/demand control such as air conditioning control and lighting control to predetermined areas in buildings or the like through the Internet. Control values used for the power supply/demand control such as air conditioning control and lighting control are calculated by operation executing units of servers or the like and distributed to facility devices installed in the areas.
It is known to equalize the calculation load of the operation by distributing the operation over a plurality of executing devices such as servers. It is also known to attempt to reduce the calculation load by performing the operation of control values used for power supply/demand control according to weather information. Specifically, it is known to attempt to reduce the calculation load by performing the operation when the weather has greatly changed and not performing the operation when the change in the weather is small.
With the relate art, however, it is difficult to smooth the calculation load at a time slot in which the weather changes continuously.